All of us deal with needing to prove something at some point or the other. It's a part of life whether we are trying to argue our case or show that something is wrong. The proof is in the pudding.

Hence, here are a half-dozen NFL veterans with something to prove as the regular season draws closer. It may be to justify that another team made a big mistake in letting them go. For others, it’s the opportunity to rebound from an injury-shortened 2012. And for some, it’s just proving they can play at all.

The stories make these men who they are. And it’s how they handle certain situations and possible adversity that makes them the professionals their current employers hope they will be.

T Eric Winston, Arizona Cardinals

It’s sometimes hard to understand why certain players jump from team to team.

In Eric Winston's case, it is even more surprising considering he used to be nothing but a certainty.

Winston is currently the starting right tackle for the Arizona Cardinals, but he previously played for the Houston Texans. One of two third-round draft choices by the team in 2006, the steady blocker started 87 straight games until the Texans released him following the 2011 season.

Winston wound up with the Kansas City Chiefs. But after one season with the club, he was cut loose just one year into a four-year contract.

Now he’s with the Cardinals and will be blocking for Carson Palmer. And if there’s any doubt that Winston has his quarterback’s back, the above video from last October should prove to be a great reminder.

RB DeAngelo Williams, Carolina Panthers

It was not that long ago the Carolina Panthers were making history. Now, the team is hoping to just make up ground in the NFC South.

Since winning a division title in 2008, the Panthers have failed to post a winning season and hit rock bottom with a 2-14 record in 2010.

One of the team’s calling card, or cards, was the backfield combination of running backs DeAngelo Williams and Jonathan Stewart. Each former first-round draft choice ran for 1,100-plus yards in 2009, making the Panthers the first team in league annals to have two players manage that feat in the same season.

Last season, Williams led the team with 173 carries but finished second in the club with 737 rushing yards, four yards behind quarterback Cam Newton. And it’s worth noting that Williams gained 210 of those yards in the season finale versus the New Orleans Saints.

Check out this recent piece by Jonathan Jones of the Charlotte Observer. Is Williams ready to become a 1,000-yard runner for the first time since 2009? If the Panthers are to make some serious noise in the NFC South, they can’t afford to have their star quarterback lead the team in rushing once again.

WR Darrius Heyward-Bey, Indianapolis Colts

Brad Penner-USA TODAY Sports

Here come the questions all over again.

In 2009, the Oakland Raiders made University of Maryland wide receiver Darrius Heyward-Bey the seventh overall pick in the draft. His rookie season was memorable for all of the wrong reasons: 11 games, nine receptions, one touchdown, countless drops.

Things would eventually get better for the former Terrapin. In his last two seasons with the Raiders (2011-12, 2012-13), Heyward-Bey snared a combined 105 passes, nine for scores.

But the former top-10 pick was part of the housecleaning in Oakland this offseason. The Indianapolis Colts grabbed him off of the open market and signed him to a one-year deal. At the time, it looked like a steal.

But those same old doubts about hanging on to the football have reared their ugly helmets once again, and his current status on the depth chart could be in doubt, writes Mike Wells of ESPN.com.

Simply put, Heyward-Bey needs to hang on to a few passes if he wants keep his full-time job.

LB Desmond Bishop, Minnesota Vikings

Sunday night in San Francisco could prove to be a big evening for linebacker Desmond Bishop.

The former Green Bay Packers standout turned Minnesota Vikings defender is hoping to earn a starting job with a team that figures to push his former team for the NFC North title in 2013.

But it’s not the job many thought he would challenge for when the Vikings signed him a few months ago following his release by the Pack. Leslie Frazier’s club was in the market for a middle linebacker.

Desmond looked like the right man for the job. In 2011, he led the Packers with 115 tackles, totaling 5.0 sacks and a pair of forced fumbles. But a hamstring tear the following preseason shelved him for all of 2012.

Instead of challenging Erin Henderson for the "Mike" position in Minnesota, Bishop is hoping to earn one of the outside jobs. And Sunday night’s tilt with the 49ers will go a long way in deciding whether or not he’s the proper fit.

OLB Trent Cole, Philadelphia Eagles

We have seen more and more of this in recent years, and certainly in numerous instances this offseason.

A number of teams have been making the switch to the 3-4 defense. And in the process, coordinators have been moving veteran defensive ends into one of the starting outside linebacking spots.

It was the case with the Indianapolis Colts and Dwight Freeney last season. This year, defensive end Will Smith will be getting a fresh start at outside linebacker in Rob Ryan’s defense in New Orleans.

Enter Trent Cole. A two-time Pro Bowl defensive end with 71 sacks in eight seasons with the Philadelphia Eagles, he’s been asked to do a little stand-up this year. And so far, there’s been nothing too funny about it.

All joking aside, it has certainly not been for a lack of trying, as Jordan Raanan of NJ.com writes. And perhaps sooner rather than later, Cole will get the nuances of his new job.

And you thought the only thing to talk about in Philadelphia was Chip Kelly’s offense.